diff --git a/overcloud.j2.yaml b/overcloud.j2.yaml
index d887ab4347..f244840142 100644
--- a/overcloud.j2.yaml
+++ b/overcloud.j2.yaml
@@ -326,7 +326,7 @@ resources:
   HorizonSecret:
     type: OS::TripleO::RandomString
     properties:
-      length: 10
+      length: 64
 
   NetCidrMapValue:
     type: OS::Heat::Value